The industrial manufacturing of articles such as garments having a three-dimensional (3D) shape and/or comprising a closed structure, such as a belt or a hoop, conventionally employs little automation, e.g. automatic sewing of the components. The rarely used automated methods are typically limited by complex equipment designs and/or low production speeds. Such sewn articles are disclosed in EP-A-0988803, relating to a panty girdle, or US-A-2004/0098784, relating to a net pant, or WO-A-01/061093, relating to boxer shorts, however the manufacturing is not on production lines employing a continuous process.
JP01284284A2 discloses a machine for continuous sewing of an annular resilient belt-form material. The machine inserts or sews a tubular elastic belt shape body, e.g. rubber ring, to tubular cloth, e.g. trousers or a skirt, continuously. The machine sews the cloth by guiding the rubber ring by a guide device having a guide plate, bending ends of tubular cloth to make a bent part, and placing endless rubber ring in the space made by the bent part and retreats to the open end side of the bent part. In U.S. application US-A-2002/0084017, a process is described for the manufacturing of a 3D article, wherein waist elastic, an insert and a 3D skirt or trunk are combined by using an expandable/retractable fixture, which is run through a process loop such as a loop conveyor system. This process and equipment however, is complex in design, and whilst the process may run automated, there are also severe limitations in the production speed.
Considering conventional pant like articles or articles to be worn on the lower torso of the wearer, such as diapers or so called training pants, and which are manufactured on high speed production lines, these are typically based on relatively simple structures. In particular the art of making disposable absorbent articles is an area where a lot of effort has been spent against efficient manufacturing of body conforming articles, and a first generation of articles was based on essentially rectangular composites, which later were improved by narrowing the composite in the crotch region when being worn, thus in the longitudinal centre region of the article. Such articles are commonly referred to as hourglass shaped articles (refer to FIG. 3E). A variant of this design, sometimes referred to as T-shaped, is an asymmetric design, where the rear waist region of the article on the wearer is significantly wider than the front region, such that the lateral extensions of the rear regions (also referred to as “back ears”) are wrapping the waist of the wearer and are connected to themselves and/or to the front region of the article.
Typically, such articles are essentially two-dimensional, i.e. made from flat panels, such as web materials, and they can be folded flat such that all connecting lines connecting various parts of the article to each other are also flat on a flat surface. Some of the designs are articles, which are pre-combined by the manufacturer, such as in a pant style, to be used e.g. as a so called training pant. Such designs comprise a waist opening and two leg openings, the leg openings separated by the crotch region of the article, and the laterally outer regions of the article corresponding to the hip region of the wearer comprise permanently or releasably connected side panels. Upon use, the side panels may be opened and re-closed e.g. for inspection of the article, or may be torn open, e.g. for removal of a loaded article.
Typically, such articles are primarily folded along a fold-line extending cross-directionally, e.g. placing front and rear ends onto each other. Additional secondary folds, such as to fold lateral extensions such as ear regions inwardly, may be folded along a longitudinal fold line.
Some of the designs as described in the above, attempt to improve the body conforming fit by introducing a three-dimensional design, whereby the article as made from essentially flat webs or panels cannot be laid flat on a flat surface with all connecting lines lying flat, too.
All such designs still have in common, that the shape is such, that, when the article is cut open along a line extending longitudinally through the side portions of the article and laid on a flat surface, the article is hourglass-shaped, i.e. narrower in the crotch region of the article than in the waist region(s).
A first approach to arrive at a fundamentally different design is described in co-pending patent applications PCT/IB05/000845, PCT/EP06/002165, or PCT/EP06/002166. Such designs comprise side portions, which are positioned—when the article is cut open or before it is assembled into its final shape—outwardly of the crotch region. Such a design may be referred to as a Plus (or +) design, as the blank for manufacturing such an article is not narrower in the crotch region but rather wider in this region, because the side-panels are arranged in this area, such that they can wrap around the outer part of the leg of the wearer. The side panel may be connected to the side crotch region of the product, i.e. to the laterally outward regions of the centre crotch region, so as to form a leg hoop, i.e. a belt like structure around the legs of the wearer during use.
Such Plus-designs exhibit great advantages in design flexibility and hence comfort of the wearer during use, without compromising sealing functionality which is desirable, e.g. in the case of absorbent articles, like diapers. As described in the mentioned documents, a particularly suitable manufacturing process employs a parallel treatment unit, such as a turret or a slide track loop, with several essentially identical treatment heads on which the articles are formed from precursor webs.
Whilst this approach allows article designs, which could hitherto not be realized on high speed manufacturing equipment, and also offers highly flexible manufacturing processes to arrive at such articles, it requires, that some of the pre-cursor web elements need to be provided un-assembled to the treatment head, on which these will be combined and folded to form the shaped article. This involves a process unit with a high number of moving elements, respective drive and sensor means. In some cases of simpler product designs, such high process flexibility may not be required, and the related investment may not be considered appropriate.
Thus, the present invention provides a significantly simpler method to make articles with hoops such as leg or waist hoops by pre-combining essentially all web elements to an essentially flat precursor blank before this precursor blank is transferred to a treatment head, where it is folded and finished to form the article. The approach will thusly be to form a pre-cursor blank in a “Plus-” or (+)-shape. On the treatment head, the respective “arms” of the Plus-shaped blank are folded downwards, and then adjacently lying edges are connected to form the article comprising closed structures, also referred to as hoops, around the legs of the wearer during use, and/or around the waist. In a preferred embodiment, the article elements are arranged during the manufacturing such that the front to back orientation in the article corresponds to the machine direction, while laterally outwardly extending side panels are oriented in cross machine direction.
Optionally, elements for forming a closed hoop in the finished article, such as waist bands, oriented and optionally elasticated along their MD direction can be attached to the side portions. As a consequence, if the article comprises a waist band, this may be connected in the front and back regions of the article, rather than in the side regions as will be inevitably the case for the conventionally manufactured articles.
The centre piece web may be cut into individual pieces on or prior to being transferred to the parallel treatment unit, e.g. after the side portions are attached thereto. In an alternative process set-up, the sequence of process steps may be such that the centre piece web is cut in discrete pieces before the laterally outwardly extending side portions are attached to the discrete centre pieces. Such sequence is particularly useful if the distance between subsequent centre pieces is to be altered, and if there are continuous webs connecting e.g. the side portions of subsequent cut pieces e.g. at their outer perimeter.
Preferably, although not necessarily, at least one major element of the article should be essentially unitary when the article web is transferred to the parallel treatment unit, to ease transfer to this unit. In the case of articles without a waist band, the centre piece of the article may be essentially unitary, i.e. to extend essentially along the full length of the article (from front through crotch to the rear), optionally combined with other elements, such as leg hoop and side-panel materials, prior to the positioning on the forming head of the parallel treatment unit, where the article web is cut, and the thusly obtained discrete articles are formed and finished. In articles with a waistband, the centre piece web may be cut in discrete pieces, and those pieces may be connected to each other by unitary waist band webs.
Thus, in one aspect, the present invention is a method for manufacturing shaped articles, which comprise at least one closed hoop structure and at least a primary and a secondary web material. The manufacturing can be performed on a high speed manufacturing equipment, which comprises a web supply means, a blank forming means, a means for cutting the blank from the web into discrete elements, a means for transferring the blanks to a parallel treatment unit, preferably a turret or an endless track. This parallel treatment unit comprises at least two web treatment sections for parallel treatment of the blanks, whereby each parallel treatment section further comprises a treatment head. Such a treatment head comprises a centre plate, being positioned essentially parallel to the surface of the parallel treatment unit, to which the blanks are transferred, longitudinal extension plates which are positioned or extending forwardly and rearwardly of the centre plate along the overall manufacturing direction of the parallel treatment unit, and which are pivotable such that the forward or rearward ends can be turned downwardly away from the surface of the parallel treatment unit whilst the respective other ends of the extension plates remain adjacent to the centre plate. Optionally, the treatment head further comprises laterally extending side plates, which may also be pivotably connected to the centre plate. The pivoting of the longitudinal and/or lateral extension plates may be achieved by drive means selected from the group of mechanical drives, preferably cam drives, pneumatic drives, or electric drives, preferably servo drives. The centre plate and/or the longitudinal and/or lateral extension plates preferably comprise a web fixation means, preferably a vacuum suction means. The treatment head further comprises connecting means for connecting portions of the blank to other portions of the blank, and fixation means to temporarily hold web materials and/or the blanks. The method thus comprises the steps of:    (a) preparing a pre-cursor blank, which comprises a centre piece comprising a primary web. The centre piece consists of a centre region, and a front and a rear region extending longitudinally from the centre region. The pre-cursor blank further comprises side portions extending laterally outwardly of both sides of the centre region comprising the secondary web, thusly forming a Plus-shaped precursor blank;    (b) transferring the pre-cursor blank to the parallel treatment unit comprising the treatment sections, each treatment section comprising a treatment head;    (c) temporarily attaching the centre region of the precursor blank to the surface of the centre plate of the treatment head which is out- or upwardly facing, and the front and rear regions to the longitudinal extension plates of the treatment head, whilst these are in an upwardly folded position essentially aligned with the centre plate;    (d) separating the primary web into individual pieces, before or after having formed the precursor blank;    (e) pivoting the outward front and rear ends of said longitudinal extension plates downwardly away from the surface of the parallel treatment unit whilst the front and rear regions of the precursor blank remain attached thereto;    (f) folding the side portions of the pre-cursor blank downwardly, so as to bring the side margins of the front and rear regions and the side margins of the side portions into an adjacent or overlapping positioning;    (g) connecting respective side margins, thereby forming a closed article comprising a hoop;    (h) optionally further treating the article;    (i) removing the article from the parallel treatment unit.
Optionally, the method can comprise a further step of    (j) adding a further web material to the pre-cursor blank.
This further web material may be essentially endless and may connect the side portions of consecutive pre-cursor blanks, preferably the laterally outward perimeter of the side portions. Preferably, this further web material is separated into segments after the precursor blank has been transferred to the treatment head, and after the longitudinal extension plates with the front and rear region attached thereto have been downwardly folded, and more preferably, this separation is executed essentially concurrently to connecting the cut edges together to form a closed hoop.
During step (a), the pre-cursor blank may comprise cut lines, which extend from the lateral outward perimeter inwardly. The side portions and the centre piece are connected by means of a connecting line or region essentially parallel and corresponding in cross-directional extension to the cut line. Also during step (a) of this method, a further material can be added for forming a leg hoop with the side portion material.
In a preferred embodiment of this method, the step (e) is executed prior to step (f) so as to create an overlap connection of the front and rear regions with the side portions forming the leg/thigh panel, such that in this overlay connection the front and rear regions are positioned outwardly, relative to the wearer during use, of the leg/thigh panels.
In a further aspect, the present invention is an article for being worn on the lower torso of a wearer comprising leg hoops for encircling a part of the upper thigh regions and a waist hoop for encircling the waist of a wearer during use. The article may further comprise a centre piece comprising a web material comprising a front region for being positioned in the front abdominal region of the wearer, and a rear region for being positioned in the lower back region of the wearer, and a centre region for being positioned in the crotch region of the wearer, and two hip/thigh panels comprising web materials for being positioned on the hips of the wearer and extending downwardly into at least the upper thigh region of the wearer. In a particular embodiment, the article may further comprise a further web material for being positioned on the inner thigh region of the wearer. In this aspect of the invention, the hip/thigh panels are connected to the centre region of the centre piece essentially only adjacently to the front respectively rear region, thereby forming the leg hoops during use. Further, the hip/thigh panels are connected to the front and back regions of the centre piece, thereby forming the waist hoop. The centre region forms a 3D/cup shape sustained by curve-linear fold lines in the lateral outward position of the centre region and by the fold lines forming connecting lines, or a perimeter of a connecting region between the centre regions and the optional further material for forming the leg hoop, if present.
The article may further comprise further material comprised in said waist hoop, which is essentially unitary within the hip regions, and which is either closed by being connected in a region corresponding to the front and/or back region of the centre piece or which forms a gap positioned in the front and/or rear region of the article. In a preferred execution, the article comprises a drawstring-type waist element, which allows easy adjustment of the gap width, e.g. by a caregiver.
Optionally, at least the centre piece further comprises liquid absorbent material and a topsheet positioned between the absorbent material and the user during use.
A particular embodiment is an article comprising an additional secondary topsheet positioned between the topsheet and the wearer during use. Preferably, the secondary topsheet is positioned at least in the centre region of the centre piece, overlaying at least partially the topsheet, and it may be connected to the topsheet in the region of the centre piece, as well as to the leg cuff forming materials in a region laterally outwardly/upwardly positioned relative to the folding or connecting line, or the perimeter of connecting region. This secondary topsheet comprises an opening for being positioned in the region of the anal opening of a wearer during use, which has an MD and an CD extension and a respective perimeter at least during use. The article may further comprise at least two elastic elements, each connected to at least a point of the perimeter or in proximity of the perimeter of the opening, whereby each two connection points are in a opposing position relative to the centre of the opening, and at least to a connection point of the topsheet or the secondary topsheet, the point being positioned outwardly away relative to the centre point of the opening, thereby creating a force to sustain the opening. In a specific embodiment, the secondary topsheet comprises a cross-directional cut line so as to form the opening positioned in the region of the anal opening of the wearer during use, wherein the elastic elements, preferably elastic threads or bands are positioned essentially aligned with the longitudinal centre line of the article. Further, the elastic elements are connected to a point on the perimeter of the cut line or to a point in the proximity of the cut line and to a point longitudinally away from the cut line, preferably in the waist region of the article, such that the tensioning of the elastic elements sustains the opening formed by the cut line.
The portions as being connected to the primary web to form the blank may be essentially of rectangular or trapezoidal form, but may also comprise a curvelinearly shaped perimeter. The side portion material may also be apertured by having openings, or may have slits, preferably in MD orientation, and preferably in a predetermined pattern.
The connecting means for the various connections in this article may preferably be glue bonding, thermo bonding, mechanical fastening means, or adhesive tape fastener.
The article may further comprise a tear line for allowing easy tearing at a predetermined location, such as to allow inspection while it is worn, and it may further optionally comprise a re-closeable connecting means arranged to re-connect the parts as separated by the tear line.
The article of the present invention is particularly suitably used as a disposable absorbent article, a baby or adult incontinence article, a training pant, a feminine care article, a menstrual pant, or pant shaped underwear.
Equal numerals in various Figures refer to corresponding elements.